The present invention relates to a throttle valve opening sensor for use with an internal combustion engine.
A conventional throttle valve opening sensor includes a substrate provided with a throttle valve opening detecting portion, a rotor adapted to be rotated in association with rotation of a throttle valve, a housing for rotatably supporting the rotor and incorporating the substrate, a packing mounted in the housing for sealing the substrate, and a contact mounted on the rotor and adapted to slide on the opening detecting portion. Air tightness of a substrate sealing part of the sensor is obtainable by using a resin filler or applying an adhesive material to the substrate fixed to the housing with a rubber packing or the like.
However, in the conventional throttle valve opening sensor, the air tightness of the substrate sealing part is deteriorated by temperature change and vibration as time is elapsed. Furthermore, workability is reduced, thereby increasing the manufacturing steps and costs.